Download App

Structure of the Atom — Science STD 9 — Question

Rajasthan BoardEnglish MediumSTD 9ScienceStructure of the Atom4 Marks
Question
Compare all the proposed models of an atom given in this chapter.
✓

Answer

Thomson
Rutherford
Bohr
  • Positively charged sphere
  • The negatively charged electrons are spread randomly all over inside the sphere
  • Positively charged = negatively charged
  • The net charge in the atom is zero.
  • Positively charged nucleus in the centre carrying the entire mass
  • The negatively charged electrons revolve in a well defined path
  • The size of atom is very large as compared to nucleus.
  • Positively charged nucleus in the centre
  • The negatively charged electrons revolving around do not radiate energy.
  • Orbits are labelled as K, L, M, N or n = 1, 2, 3, 4
Thomson:

Rutherford:

Bohr:

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "Que-Ans (Each of 4 Mark )" from Structure of the Atom→Structure of the Atom — all question types→Science STD 9 question papers→Rajasthan Board STD 9 question papers→Rajasthan Board question paper generator→

Similar questions

How would you prepare a saturated solution of sodium chloride in water at 25°C? What will happen if this solution is cooled to 10°C?
→
Discuss the various methods which are used to control plant diseases.
→
State and explain the law of conservation of energy with an example.
→
Describe structure and functions of plasma membrane.
→
Show by using the graphical method that:$\text{s}=\text{ut}+\frac{1}{2}\text{at}^2$
where the symbols have their usual meanings.
→
Name two indigenous and two exotic breeds of poultry. Write a note on egg production and broiler production.
→
A gun of mass $3\ kg$ fires a bullet of mass $30g.$ The bullet takes $0.003s$ to move through the barrel of the gun and acquires a velocity of $100\ m/s.$ Calculate:
  1. The velocity with which the gun recoils.
  2. The force exerted on gunman due to recoil of the gun.
→
Study the speed-time graph of a car given alongside and answer the following questions:
  1. What type of motion is represented by OA?
  2. What type of motion is represented by AB?
  3. What type of motion is represented by BC?
  4. What is the acceleration of car from O to A?
  5. What is the acceleration of car from A to B?
  6. What is the retardation of car from B to C?
→
A sound producing body is at considerable distance from a man. There can be four different media W, X, Y and Z between the sound producing body and the man. The medium X brings the sound to man most quickly whereas medium Z takes the maximum time. The time taken by medium W in bringing sound to man is less than that of X but more than that of Z. The medium Y, however, fails to bring the sound from the sound producing body to the man. Which medium could be the one:
  1. Having no fixed shape and no fixed volume?
  2. Having a fixed volume but no fixed shape?
  3. Having the same composition as that on the moon?
  4. Having a fixed shape and a fixed volume?
→
Give the chemical formulae for the following compounds and compute the ratio by mass of the combining elements in each one of them.
  1. Ammonia
  2. Carbon monoxide
  3. Hydrogen chloride
  4. Aluminium fluoride
  5. Magnesium sulphide
→